Fowler and Turvey, etc. references

[Avery Andrews 930908.1827]

There's actually lots of useful stuff in these papers--in the remarks
I'm complaining about the misreprentations, etc. of PCT, but there's
plenty of empirical substance as well (which I haven't gotten as
deeply into as I ought and would like to).

Fowler, C. and Turvey, M. (1978), Skill acquisition: an event approach
with special reference to the problem of searching for the optimum of
a function of several variables', In G. Stelmach (Ed.) Information
processing in motor control and learning. NY: Academic Press, 1978).
esp. pgs. 26-31.

  shows that they (a) didn't understand how 2nd order control systems
  actually work (b) didn't read or think about Bills' chapter on
  coordination. The paper is discussed by Rick in Marken, R.S.
  (1986) 'Perceptual Organization of Behavior: A Hierarchical Control
  Model of Coordinated Action,' Journal of Experimental Psychology:
  Human Perception and Performance, 12:267-276, also in the Mind
  Readings book available from Greg Williams. Rick solves the problems
  they pose, but is much too gentle in his overall handling of the
  paper, I'd say.

Kelso, Turvey et. al (1980) `On the concept of coordinative structures
as dissiptative structures I: theoretical line', in Stelmach and
Requin, eds., _Tutorials in Motor Behavior_, North Holland, pgs 1-47.

  confuses cognitivist and control theory in various ways (I can't find
  my actual copy of it. & am not sure who all the authors are). R.A.
  Schmidt's article in this book is instructive reading, too.

Fowler, C.A., P. Rubin, R.E. Remez and M.T Turvey (1980) `Implications
of Speech Production for a General Theory of Action', in Butterworth, B.
_Language Production, Vol 1, Speech and Talk_, Academic Press,
pp. 373-420, esp. pp. 489-401.

  similar to Fowler & Turvey (1978) in its treatment of PCT.

Kugler, Peter Noble. Information, natural laws, and self-assembly of
rhythmic movement / Peter Noble Kugler, Michael T. Turvey. Hillsdale,
N.J : L. Erlbaum Associates, 1987.

  The most recent version of the `neo-Gibsonian' dismissal of control theory.
  I find the whole book rather perplexing, and much of it I can't
  understand at all (not enough math to tell whether it's good oil or
  b.s.). But some of the basic assumptions seem to me to be deeply
  flawed.

Another interesting piece of reading is:

Abbs and Winstein (1990: `Functional Contributions of Rapid and Automatic
Sensory-Based Adjustments to Motor Output', in Jeannerod, M (ed)
_Attention and Performance_ XIII, 627-652.

This spends quite a lot of time summarising information about
the speed of various feedback loops (refuting claims that are often made
that feedback is `too slow' to be useful for various things).
But then they go on, in a section headed `Contributions outside the
closed-loop model' (p. 635):

  "Technically, a _feedback_ sysem is one which an error signal directly
drives a corrective adjustment at the site where that error is
introduced. Recent experimental data indicate that many (or most)
important contributions of sensory information to the on line control of
movement are not captured by this fundamental construct."

An example of something not captured is supposed to be automatic
adjustment of lip aperture in the production of rounded speech sounds,
whereby, if one lip is prevented from moving, the other will move
further to compensate (this is a `distributed compensatory response').

From our point of view, this is just feedback, where what is being

controlled is `kinesthetically' perceived lip aperture, and the motor
output is driving signals to lip muscles (so, if one lip is inhibited
from moving, the driving signals to both will continue until the
movement of the other is sufficient to reduce the total aperture to the
desired amount (ignoring dynamic subtleties)). We can't make any sense out of
the verbiage about `corrective adjustment at the site where the error
is introduced', nor can we find any source for it in the technical
literature (tho there is supposed to be an old IEEE document from the
fifties where various terms are defined in ways that are often not
observed in practice -- I haven't gotten around to tracking this
document down). Insofar as I can impose any sort of interpretation on
the verbiage, it would rule out thermostats from being feedback systems,
since an error might be introduced in the front hall when the door is
opened, and corrected in the basement when the furnace comes on. I'd
guess that this `technical' interpretation is a misconception gotten
from engineering text diagrams where the feedback takeoff comes off the
arrow labelled `output', but this kind of diagram is wrong for
psychology, as Bill has discussed recently (incidently, N. Bernstein's
feedback diagram was a lot more like Bill's, tho burdened with
some inessentials, I think).

Re Jack Adams, I'm reassured that we're not surprised by each other's
opinions! But it seems to me that he was/is taken rather seriously by
the motor-behavior people (Schmidt, et. al.), who strike me as being
anything but deep thinkers. But these are the people who did the work
that people refer to when writing off feedback theory. There also seems
to be some sort of disciplinary divide between motor control people and
physiologists (Houk and Rymer, for example), who strike me as being *much*
cluier about feedback. For example, much is made in the anti-feedback
literature about the fact that deafferented organisms are not completely
disabled, but

  Sanes, J. (1990) `Motor Representations in Deafferented Humans:
  A Mechanism for Disordered Movement Performance.', in _Attention
  & Performance XIII_, 714-735.

shows that people who are effectively deafferented (by `large fiber
sensory neuropathy') do have substantial deficits. He also argues that
Bizzi's `equilibrium point' hypothesis about limb-positioning is false
for humans under normal conditions, whatever its merits may be for
monkeys under the rather odd circumstances that Bizzi set up in his
experiments.

Speaking of depth, I should probably point out that I have zero
credentials in this area - what I am by trade is a Chomskyan
syntactican. But I have done a bit of reading around in the motor
control area, & hope to return to it soon (well, syntax is a wildly
elaborated subcase of motor control, isn't it ...).

Avery.Andrews@anu.edu.au